Electrochemical cells may be of a flooded or “wet” configuration, utilizing a liquid electrolyte to conduct ions and support electrochemical reactions between an anode and a cathode. Although some electrochemical cells, such as those in the lead-acid batteries may utilize a static amount of electrolyte in a pool, other electrochemical cells may utilize a flow configuration. In such a flow configuration, electrolyte may flow through the cell, potentially from and/or to a reservoir configured to hold an excess of electrolyte. Flooded electrochemical cells of both flow or static configurations may be of numerous types, including but not limited to lead-acid, metal-air, Ni—Zn, Ag—Zn, and Ni—Cd. One example of a metal-air electrochemical cell typically comprises a fuel electrode serving as the anode, at which metal fuel is oxidized, and an oxidant electrode that serves as an air breathing cathode, at which oxygen from ambient air is reduced. An electrolyte of the cell may support reactions of the oxidized/reduced ions. For example, see U.S. Patent Application Publication No. 2009/0284229, incorporated in its entirety herein by reference.
In some electrochemical cells, particulates or precipitates of the metal fuel may detach from the fuel electrode, either during consumption of the metal fuel during a discharge mode, or when the metal fuel is being reduced onto the fuel electrode during a recharge mode. This loss of active material may lead to reduced capacity of the battery, thereby reducing its lifetime. Furthermore, any active material that detaches and flows in the electrolyte in flow configuration cells may collect/agglomerate in a way that may short electrodes in the cell, thereby affecting battery/cell performance. Various attempts at managing these particulates and/or precipitates in electrochemical cells are known. For example, one such device is shown in U.S. patent application Ser. No. 12/901,410, published as U.S. Patent Application Publication No. 2011/0086278, incorporated in its entirety herein by reference.
The present application also endeavors to provide an effective and improved way of reclaiming fuel in the form of precipitates or particles that separate from the fuel electrode, to reduce precipitate congestion in the cell and retain the capacity and performance of the cell.